Special Thanks & Weird -25% LTFT

**91parkave** · 08-23-2013

you can take my trans tables and try them out , see if you like the way it responds just use the compare function

https://docs.google.com/file/d/0B2Tw...it?usp=sharing

**Fivefingerdeathpunch** · 08-23-2013

Closed loop is like when your like bumming around on the freeway or at a set speed and the computer goes for economy. The o2 mv can show you it.

Open loop pretty much just doesnt use the o2 for feedback, so you can make the car run however you want by using a VE table.

**matt5112** · 08-24-2013

Originally Posted by 91parkave

I keep forgetting about that, most people just deal with MAF only, and it works, however i rather have that failsafe incase of maf failure and i like that it seems to be a little more crisper running them blended. just my .02

Actually, the 3800 pcm still won't even do that with a VE tune.

The 3800 pcm uses a default MAF airflow table instead.

For example, I changed my VE from 60 to 160 and the fueling hardly changed at all.

LSx cars need a good VE tune because the transient fueling is based on it. The MAF only takes over on steady acceleration.

**SnowFlake** · 08-24-2013

FWIW, I have a LS1 MAF on my turbo setup, Danomite has a LS1 MAF on his twin charge setup... we both use MAF charts that are stock LS1.
Both of our cars run awesome and make quite a bit of power. Our intake tracts are quite different, and vary wildly from our blower setups.

I've never had much luck with, nor seen a reason to adjust a given MAF curve.
In any tune I've ever dealt with where someone came to me with their MAF adjusted, 99% of their issues were fixed by going back to the stock (for their respective sensor) curve.

**rperry435** · 08-25-2013

If I had never adjusted my maf curve I would have remained -25% LTFT. By adjusting it properly I'm within 3-5% across the board. So in my case it was definitely needed.

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**rperry435** · 08-25-2013

Originally Posted by 91parkave

looks pretty good i would lean out the COT just a hair to get you closer to 11AFR at wot. Im thinking its adding a little to much fuel, according to youre wideband. MAF looks great but the VE table could use a tad more work. i use a filter string on mine to help filter some decel and other variable data out of the equation [PID.6310]<12 see if that helps...BTW your trans tables could use some definate work. but thats on you.

I just turned of COT. I dont have a cat